Move HTML templates into lib/templates and other clean up.

[kallentu]

• Removed the superParametersAllowed and enhancedEnumsAllowed experiment bools for testing since we don't use them. enhancedEnumsAllowed is enabled by default now anyways.
• Moved all templates from lib/templates/html to lib/templates and deleted the html folder.
• Removed the md templates from the Renderer.

#3535

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[srawlins]

Ooh nice.